/* 计算MVV(LVA)值的函数
*
* MVV(LVA)指的是：如果被吃子无保护，那么取值MVV，否则取值MVV-LVA。
* 由于ElephantEye的MVV(LVA)值在计算完毕后再加了1，并且有其它考虑，因此有以下几种含义：
* a. MVV(LVA)大于1，说明被吃子价值大于攻击子(表面上是赚的)，这种吃子将首先搜索，静态搜索也将考虑这种吃子；
* b. MVV(LVA)等于1，说明被吃子有一定价值(吃车马炮或吃过河兵卒，即便表面上是亏的，也值得一试)，静态搜索也将考虑这种吃子；
* c. MVV(LVA)等于0，说明被吃子没有价值，静态搜索将不考虑这种吃子。
*
* MVV价值表"SIMPLE_VALUE"是按照帅(将)=5、车=4、马炮=3、兵(卒)=2、仕(士)相(象)=1设定的；
* LVA价值直接体现在吃子着法生成器中。
*/
int PositionStruct::MvvLva(int sqDst, int pcCaptured, int nLva) const {
int nMvv, nLvaAdjust;
nMvv = SIMPLE_VALUE(pcCaptured);
nLvaAdjust = (Protected(OPP_SIDE(sdPlayer), sqDst) ? nLva : 0);
if (nMvv >= nLvaAdjust) {
return nMvv - nLvaAdjust + 1;
} else {
return (nMvv >= 3 || HOME_HALF(sqDst, sdPlayer)) ? 1 : 0;
}
}
int _PositionStruct::GenerateMovesFrom(int sqSrc, int *mvs, BOOL bCapture) const {
int i, j, nGenMoves, nDelta, sqDst;
int pcSelfSide, pcOppSide, pcSrc, pcDst;
nGenMoves = 0;
pcSelfSide = SIDE_TAG(sdPlayer);
pcOppSide = OPP_SIDE_TAG(sdPlayer);
if (sqSrc >= 0 && sqSrc < 256) {
pcSrc = ucpcSquares[sqSrc];
if ((pcSrc & pcSelfSide) == 0) {
return nGenMoves;
}
switch (pcSrc - pcSelfSide) {
case PIECE_KING:
for (i = 0; i < 4; i ++) {
sqDst = sqSrc + ccKingDelta[i];
if (!IN_FORT(sqDst)) {
continue;
}
pcDst = ucpcSquares[sqDst];
if (bCapture ? (pcDst & pcOppSide) != 0 : (pcDst & pcSelfSide) == 0) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
}
break;
case PIECE_ADVISOR:
for (i = 0; i < 4; i ++) {
sqDst = sqSrc + ccAdvisorDelta[i];
if (!IN_FORT(sqDst)) {
continue;
}
pcDst = ucpcSquares[sqDst];
if (bCapture ? (pcDst & pcOppSide) != 0 : (pcDst & pcSelfSide) == 0) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
}
break;
case PIECE_BISHOP:
for (i = 0; i < 4; i ++) {
sqDst = sqSrc + ccAdvisorDelta[i];
if (!(IN_BOARD(sqDst) && HOME_HALF(sqDst, sdPlayer) && ucpcSquares[sqDst] == 0)) {
continue;
}
sqDst += ccAdvisorDelta[i];
pcDst = ucpcSquares[sqDst];
if (bCapture ? (pcDst & pcOppSide) != 0 : (pcDst & pcSelfSide) == 0) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
}
break;
case PIECE_KNIGHT:
for (i = 0; i < 4; i ++) {
sqDst = sqSrc + ccKingDelta[i];
if (ucpcSquares[sqDst] != 0) {
continue;
}
for (j = 0; j < 2; j ++) {
sqDst = sqSrc + ccKnightDelta[i][j];
if (!IN_BOARD(sqDst)) {
continue;
}
pcDst = ucpcSquares[sqDst];
if (bCapture ? (pcDst & pcOppSide) != 0 : (pcDst & pcSelfSide) == 0) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
}
}
break;
case PIECE_ROOK:
for (i = 0; i < 4; i ++) {
nDelta = ccKingDelta[i];
sqDst = sqSrc + nDelta;
while (IN_BOARD(sqDst)) {
pcDst = ucpcSquares[sqDst];
if (pcDst == 0) {
if (!bCapture) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
} else {
if ((pcDst & pcOppSide) != 0) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
break;
}
sqDst += nDelta;
}
}
break;
case PIECE_CANNON:
for (i = 0; i < 4; i ++) {
nDelta = ccKingDelta[i];
sqDst = sqSrc + nDelta;
while (IN_BOARD(sqDst)) {
pcDst = ucpcSquares[sqDst];
if (pcDst == 0) {
if (!bCapture) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
} else {
break;
}
sqDst += nDelta;
}
sqDst += nDelta;
while (IN_BOARD(sqDst)) {
pcDst = ucpcSquares[sqDst];
if (pcDst != 0) {
if ((pcDst & pcOppSide) != 0) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
break;
}
sqDst += nDelta;
}
}
break;
case PIECE_PAWN:
sqDst = SQUARE_FORWARD(sqSrc, sdPlayer);
if (IN_BOARD(sqDst)) {
pcDst = ucpcSquares[sqDst];
if (bCapture ? (pcDst & pcOppSide) != 0 : (pcDst & pcSelfSide) == 0) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
}
if (AWAY_HALF(sqSrc, sdPlayer)) {
for (nDelta = -1; nDelta <= 1; nDelta += 2) {
sqDst = sqSrc + nDelta;
if (IN_BOARD(sqDst)) {
pcDst = ucpcSquares[sqDst];
if (bCapture ? (pcDst & pcOppSide) != 0 : (pcDst & pcSelfSide) == 0) {
mvs[nGenMoves] = MOVE(sqSrc, sqDst);
nGenMoves ++;
}
}
}
}
break;
}
}
return nGenMoves;
}
// 棋子保护判断
bool PositionStruct::Protected(int sd, int sqSrc, int sqExcept) const {
// 参数"sqExcept"表示排除保护的棋子(指格子编号)，考虑被牵制子的保护时，需要排除牵制目标子的保护
int i, sqDst, sqPin, pc, x, y, nSideTag;
SlideMaskStruct *lpsmsRank, *lpsmsFile;
// 棋子保护判断包括以下几个步骤：
__ASSERT_SQUARE(sqSrc);
nSideTag = SIDE_TAG(sd);
if (HOME_HALF(sqSrc, sd)) {
if (IN_FORT(sqSrc)) {
// 1. 判断受到帅(将)的保护
sqDst = ucsqPieces[nSideTag + KING_FROM];
if (sqDst != 0 && sqDst != sqExcept) {
__ASSERT_SQUARE(sqDst);
if (KING_SPAN(sqSrc, sqDst)) {
return true;
}
}
// 2. 判断受到仕(士)的保护
for (i = ADVISOR_FROM; i <= ADVISOR_TO; i ++) {
sqDst = ucsqPieces[nSideTag + i];
if (sqDst != 0 && sqDst != sqExcept) {
__ASSERT_SQUARE(sqDst);
if (ADVISOR_SPAN(sqSrc, sqDst)) {
return true;
}
}
}
}
// 3. 判断受到相(象)的保护
for (i = BISHOP_FROM; i <= BISHOP_TO; i ++) {
sqDst = ucsqPieces[nSideTag + i];
if (sqDst != 0 && sqDst != sqExcept) {
__ASSERT_SQUARE(sqDst);
if (BISHOP_SPAN(sqSrc, sqDst) && ucpcSquares[BISHOP_PIN(sqSrc, sqDst)] == 0) {
return true;
}
}
}
} else {
// 4. 判断受到过河兵(卒)横向的保护
for (sqDst = sqSrc - 1; sqDst <= sqSrc + 1; sqDst += 2) {
// 如果棋子在边线，那么断言不成立
// __ASSERT_SQUARE(sqDst);
if (sqDst != sqExcept) {
pc = ucpcSquares[sqDst];
if ((pc & nSideTag) != 0 && PIECE_INDEX(pc) >= PAWN_FROM) {
return true;
}
}
}
}
// 5. 判断受到兵(卒)纵向的保护
sqDst = SQUARE_BACKWARD(sqSrc, sd);
// 如果棋子在底线，那么断言不成立
// __ASSERT_SQUARE(sqDst);
if (sqDst != sqExcept) {
pc = ucpcSquares[sqDst];
if ((pc & nSideTag) != 0 && PIECE_INDEX(pc) >= PAWN_FROM) {
return true;
}
}
// 6. 判断受到马的保护
for (i = KNIGHT_FROM; i <= KNIGHT_TO; i ++) {
sqDst = ucsqPieces[nSideTag + i];
if (sqDst != 0 && sqDst != sqExcept) {
__ASSERT_SQUARE(sqDst);
sqPin = KNIGHT_PIN(sqDst, sqSrc); // 注意，sqSrc和sqDst是反的！
if (sqPin != sqDst && ucpcSquares[sqPin] == 0) {
return true;
}
}
}
x = FILE_X(sqSrc);
y = RANK_Y(sqSrc);
lpsmsRank = RankMaskPtr(x, y);
lpsmsFile = FileMaskPtr(x, y);
// 7. 判断受到车的保护，参阅"position.cpp"里的"CheckedBy()"函数
for (i = ROOK_FROM; i <= ROOK_TO; i ++) {
sqDst = ucsqPieces[nSideTag + i];
if (sqDst != 0 && sqDst != sqSrc && sqDst != sqExcept) {
if (x == FILE_X(sqDst)) {
if ((lpsmsFile->wRookCap & PreGen.wBitFileMask[sqDst]) != 0) {
return true;
}
} else if (y == RANK_Y(sqDst)) {
if ((lpsmsRank->wRookCap & PreGen.wBitRankMask[sqDst]) != 0) {
return true;
}
}
}
}
// 8. 判断受到炮的保护，参阅"position.cpp"里的"CheckedBy()"函数
for (i = CANNON_FROM; i <= CANNON_TO; i ++) {
sqDst = ucsqPieces[nSideTag + i];
if (sqDst && sqDst != sqSrc && sqDst != sqExcept) {
if (x == FILE_X(sqDst)) {
if ((lpsmsFile->wCannonCap & PreGen.wBitFileMask[sqDst]) != 0) {
return true;
}
} else if (y == RANK_Y(sqDst)) {
if ((lpsmsRank->wCannonCap & PreGen.wBitRankMask[sqDst]) != 0) {
return true;
}
}
}
}
return false;
}
